Thermal properties and surface reactivity in simulated body fluid of new strontium ion-containing phosphate glasses.

In this paper, we investigate the effect of SrO substitution for CaO in 50P₂O₅-10Na₂-(40-x)CaO-xSrO glass system (x from 0 to 40) on the thermal and structural properties and also on the glass reactivity in simulated body fluid (SBF) in order to find new glass candidates for biomedical glass fibers. The addition of SrO at the expense of CaO seems to restrain the leaching of phosphate ions in the solution limiting the reduction of the solution pH. We observed the formation of an apatite layer at the surface of the glasses when in contact with SBF.

Planar waveguides formed by Ag+-Na+ ion exchange in nonlinear optical glasses: diffusion and optical properties.

All-optical communication systems are the subject of intense research related to the integration of nonlinear optical materials. In sodiocalcic borophosphate glasses that contain niobium oxide and exhibit high nonlinear optical indices, planar waveguides have been formed by a Ag(+)-Na(+) ion-exchange technique. WKB analysis has been used to characterize the diffusion profiles of silver ions exchanged in glass substrate samples chemically by an electron microprobe technique and optically by an M-line technique.

[Quality of medicines in least developed countries].

Due to worsening economic conditions and poor enforcement of existing pharmaceutical and customs regulations, third world countries are faced with a growing threat from counterfeit and substandard medicines. With the expansion of illicit markets in urban areas, the sales of medicines of uncertain quality and origin are increasing. Most victims of this illicit trade are among the world's poorest populations that cannot afford to buy quality drugs through private-sector distribution channels.

[Access for all to quality drugs].

The implementation of essential drugs policies and widespread use of generic products in humanitarian programs has ensured access to medication for poverty-stricken populations. However rigorous drug selection according to origin is necessary to guarantee quality. A drug is more than a mixture of chemical components, it depends on a complex balance that can be affected by numerous factors.